Logic finfet high-k/conductive gate embedded multiple time programmable flash memory

ABSTRACT

A method for fabricating a multiple time programmable (MTP) device includes forming fins of a first conducting type on a substrate of a second conducting type. The method further includes forming a floating gate dielectric to partially surround the fins. The method also includes forming a floating gate on the floating gate dielectric. The method also includes forming a coupling film on the floating gate and forming a coupling gate on the coupling film.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.14/044,725, filed on Oct. 2, 2013, entitled “LOGIC FINFETHIGH-K/CONDUCTIVE GATE EMBEDDED MULTIPLE TIME PROGRAMMABLE FLASHMEMORY,” which claims the benefit under 35 U.S.C. §119(e) of co-pendingand commonly-assigned U.S. Provisional Patent Application No.61/860,481, filed on Jul. 31, 2013, entitled “LOGIC FINFETHIGH-K/CONDUCTIVE GATE EMBEDDED MULTIPLE TIME PROGRAMMABLE FLASHMEMORY,” the disclosures of which are expressly incorporated byreference herein in their entireties.

BACKGROUND

1. Field

Aspects of the present disclosure relate to semiconductor devices, andmore particularly to a high-k/conductive gate embedded flash multipletime programmable (MTP) non-volatile memory.

2. Background

In semiconductor devices, memory is often used to configure thefunctions of logic blocks and the routing of interconnections betweendevices and circuits. For power and size considerations, programmablenon-volatile memories (NVM), (e.g., multiple time programmable (MTP)non-volatile memories), may be used to allow for customization ofcircuit operation.

NVM MTP memories may be fabricated from complementarymetal-oxide-semiconductor (CMOS) circuits using field-effect transistor(FET) components. Recently, different structures for the transistors inCMOS have been introduced, where the transistor is a “fin” shaped (3D)structure. These structures are often referred to as “FinFET”structures.

There are some associated problems with using FinFETs in CMOSnon-volatile memory applications. FinFETs may use additional voltage tocouple a floating gate structure to the fin. Because the upper portionof the fin area (the width of the fin times the length) is often small,an additional program (write) voltage is used to couple the gatestogether in series, which may negate the power savings realized in CMOScircuitry. Further, MOS diodes used for coupling, (e.g., for thefloating gate of a memory cell), only bias in a positive direction.Positive-only biasing makes it difficult for negative voltages to beused to program (“write to”) or erase to/from a floating gate memorycell.

SUMMARY

A method of fabricating a multiple time programmable (MTP) device inaccordance with an aspect of the present disclosure includes formingfins of a first conducting type on a substrate of a second conductingtype. The method further includes forming a floating gate dielectric topartially surround the fins. The method also includes forming a floatinggate on the floating gate dielectric. The method also includes forming acoupling film on the floating gate. The method also includes forming acoupling gate on the coupling film.

A multiple time programmable (MTP) device in accordance with anotheraspect of the present disclosure includes a substrate. Such a devicealso has a fin having a first wall, a second wall, and a surfaceconnecting the first wall and the second wall, the first wall and thesecond wall adjoining the substrate. Such a device also includes afloating gate dielectric having a first dielectric surface on the firstwall of the fin and a second dielectric surface on the surface of thefin. Such a device also includes a floating gate on the floating gatedielectric. Such a device also includes a coupling film on the floatinggate. A coupling gate is provided on the coupling film.

A multiple time programming (MTP) device in accordance with anotheraspect of the present disclosure includes means for conducting current.Such a device also includes means for storing charges that control thecurrent in the conducting means. The device also includes means forcontrolling the charges stored on the storing means.

This has outlined, rather broadly, the features and technical advantagesof the present disclosure in order that the detailed description thatfollows may be better understood. Additional features and advantages ofthe disclosure will be described below. It should be appreciated bythose skilled in the art that this disclosure may be readily utilized asa basis for modifying or designing other structures for carrying out thesame purposes of the present disclosure. It should also be realized bythose skilled in the art that such equivalent constructions do notdepart from the teachings of the disclosure as set forth in the appendedclaims. The novel features, which are believed to be characteristic ofthe disclosure, both as to its organization and method of operation,together with further objects and advantages, will be better understoodfrom the following description when considered in connection with theaccompanying figures. It is to be expressly understood, however, thateach of the figures is provided for the purpose of illustration anddescription only and is not intended as a definition of the limits ofthe present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, referenceis now made to the following description taken in conjunction with theaccompanying drawings.

FIG. 1 illustrates a schematic of a CMOS floating gate nonvolatilememory (NVM) cell in an aspect of the present disclosure.

FIG. 2 illustrates a schematic of a CMOS floating gate NVM cell inanother aspect of the present disclosure.

FIG. 3 illustrates a schematic of a CMOS floating gate NVM cell inanother aspect of the present disclosure.

FIGS. 4 and 5 illustrate schematics of other aspects of CMOS floatinggate NVM cells in accordance with the present disclosure.

FIGS. 6A and 6B illustrate birds-eye views of a FinFET floating gate NVMtransistor in accordance with various aspects of the present disclosure.

FIGS. 7A and 7B illustrate cutaway views of the structures shown inFIGS. 6A and 6B, respectively.

FIG. 8 illustrates a birds-eye view of FinFET floating gate NVMtransistors including an erase gate structure in accordance with anaspect of the present disclosure.

FIGS. 9 and 10 illustrate cutaway views of a FinFET NVM structure in anaspect of the present disclosure.

FIG. 11 illustrates a cutaway view of a transistor in accordance with anaspect of the present disclosure.

FIGS. 12 through 15 illustrate a process construction flow oftransistors in accordance with an aspect of the present disclosure.

FIG. 16 illustrates an operation control table in accordance with anaspect of the present disclosure.

FIG. 17 illustrates a process flow in accordance with an aspect of thepresent disclosure.

FIG. 18 is a block diagram showing an exemplary wireless communicationsystem in which an aspect of the disclosure may be advantageouslyemployed.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to represent the only configurationsin which the concepts described herein may be practiced. The detaileddescription includes specific details for the purpose of providing athorough understanding of the various concepts. It will be apparent tothose skilled in the art, however, that these concepts may be practicedwithout these specific details. In some instances, well-known structuresand components are shown in block diagram form in order to avoidobscuring such concepts. As described herein, the use of the term“and/or” is intended to represent an “inclusive OR”, and the use of theterm “or” is intended to represent an “exclusive OR”.

One aspect of the present disclosure is directed to a process tofabricate a multiple time programmable (MTP) NVM cell for flash memory.The process includes forming a high-k gate dielectric film on n-wells orp-wells in a substrate, and then forming a conductive gate (gate first)or dummy poly gate (gate last) on the high-k gate dielectric film. Theconductive gates and/or poly gate may be a floating gate. Afterwards,other process steps may occur, such as forming spacers on the conductivegates, forming source/drain regions in the n/p-wells, removing the dummypoly gate and filling the conductive gate for a second dummy poly gatelast case. Other steps include forming contacts in the source/drainregions, and forming a cap layer on the gates and the contacts.

FIG. 1 illustrates a schematic of a PMOS FinFET floating gate NVM cell.Representatively, a memory cell 100 includes a control transistor 102(also referred to as coupling gate 102), a program transistor 104, and,optionally, an erase transistor 106 (also referred to as an erasegate/capacitor 106). The coupling gate 102, the gate of the programtransistor 104, and, optionally, the gate of the erase gate/capacitor106 are coupled together at the floating gate 108. The drain 110, thesource 112, and the well (which may be an n-doped well) 114 are shownfor the program transistor 104. There can also be a word line accesstransistor in series (not shown). This would be a four PMOS transistorfloating gate FinFET NVM cell. It also can be a four NMOS transistorfloating gate FinFET NVM cell.

As shown in FIG. 2, in an aspect of the present disclosure, the couplinggate 102 is a plate capacitor. To program the program transistor 104,the source 112, which is coupled to a bit line (BL) 202, is brought to alow voltage, which may be ground. In addition, the drain 110, which iscoupled to a source line (SL) 200, is brought to a higher voltage, whichmay be the operating voltage or the supply voltage (Vdd). To turn on theprogram transistor 104, the voltage across the coupling gate 102 isnegative raised, for example, by applying a negative voltage to the wordline (WL) or control gate (CG) 206. The word line/control gate 206 isthe conduction path of the coupling gate 102. When the coupling gate 102receives a negative bias, negative charge is induced on the couplinggate 102, inducing negative charge on the floating gate 108 of theprogram transistor 104. The floating gate 108 may use an n-typeconductive gate for PMOS devices for improved data retention. Thisallows the channel in the program transistor 104 to turn on and conduct.A conducting program gate of the program transistor 104 indicates aparticular logic level whereas a non-conducting program gate of theprogram transistor 104 indicates a different logic level with positivecharge inside the floating gate 108. The program floating device can bean NMOS floating gate device. The floating gate 108 may use a p-typeconductive gate for NMOS devices for improved data retention. FIG. 2shows a one transistor floating gate NVM cell.

Another aspect of the present disclosure, shown in FIG. 3, includes theerase gate/capacitor 106 as part of the memory cell 100. When the erasegate/capacitor 106 is biased by voltage of the erase gate/capacitor 106,in optional conjunction with changing the voltage on the wordline/control gate 206, the charge at the floating gate 108 is reducedsuch that the program transistor 104 no longer has enough electricalcharge on the floating gate 108 to shut off current between the sourceline 200 and the bit line 202. The floating gate 108 may use an n-typeconductive gate for PMOS devices for better data retention. This“erases” the program transistor 104. The program floating device canalso be an NMOS floating gate device. The floating gate 108 may use ap-type conductive gate for NMOS devices for better data retention. Theprogram floating device can also be an NMOS floating gate device. Thefloating gate 108 may use a p-type conductive gate for NMOS devices forimproved data retention. FIG. 3 shows a two transistor floating gate NVMcell.

FIGS. 4 and 5 illustrate schematics of other aspects of PMOS floatinggate NVM cells in accordance with the present disclosure.

As shown in FIG. 4, the control gate (CG) 400 may be separated from theword line gate 406 (as opposed to being a combined word line/controlgate 206 as shown in FIG. 2) by including an access transistor 402coupled to the source 112 of the program transistor 104. The bit line202 is then coupled to the source of the access transistor 402, and theword line gate 406 is coupled to the gate of the access transistor 402.FIG. 4 shows a two transistor floating gate NVM cell.

As shown in FIG. 5, the schematic of FIG. 4 can include an erasegate/capacitor 106. FIG. 5 shows a four transistor floating gate NVMcell. The floating gate 108 may use an n-type conductive gate for PMOSdevices for better data retention. The program floating device can alsobe an NMOS floating gate device. The floating gate 108 may use a p-typeconductive gate for NMOS devices for better data retention.

FIG. 6A illustrates a cutaway view of a FinFET floating gate transistorin accordance with an aspect of the present disclosure.Representatively, a substrate 600 supporting an n-well 602 is shown (forPMOS devices). An oxide layer 604, which may be a shallow trenchisolation (STI) oxide layer 604, is coupled to the substrate 600 and aportion of the oxide layer 604 is opened to expose the n-well 602. A finstructure 606 with a width and a height is formed, and a gate oxidelayer 608 is formed around the fin structure 606. The gate oxide layer608 may be silicon oxide, or may be a dielectric or other material witha different dielectric constant (k) than silicon oxide, such as AluminumOxide, Hafnium Oxide, Hafnium Oxide Nitride, Zirconium Oxide, laminatesand/or alloys of these materials. Other materials may be used withoutdeparting from the scope of the present disclosure.

A thickness-adjustable oxide may also be coupled to the gate oxide layer608. Further, the gate oxide layer 608 may be a high-k dielectricmaterial. A “high-k dielectric material” is a dielectric material with adielectric constant k greater than the dielectric constant of silicondioxide. For the same actual thickness, a high-k material will providemore capacitance per unit area than silicon dioxide. The high-k gatedielectric film may be made of, for example, Silicon Nitride (SiN),Silicon Carbide (SiC), Aluminum Oxide (Al2O3), Hafnium Oxide (HfOx),Hafnium Oxide Nitride, Zirconium Oxide, combinations or laminations ofthese or other materials, etc. These materials are used by standardlogic FinFET processes and also used in FinFET floating gate devices inthe memory cell 100. Use of high-K materials may also improve logicdevice performance for scaling technology, be used in a multiple timeprogrammable memory, such as the memory cell 100.

As channel sizes in transistors become smaller, the thickness of thedielectric region in the gate oxide layer 608, and the thickness of acoupling film 610, is often reduced. The dielectric constant k of thegate oxide layer 608, along with the thickness of the gate oxide layer608, has a heightened effect on the control of the floating gate 108over the channel of the program transistor 104 (between the source 112and the drain 110) (FIG. 1).

A high-k material allows for higher capacitance across the width of thematerial. Therefore, a high-k material can be used with a smallerchannel size. The increased capacitive coupling accommodates the smallerchannel size, allowing the gate to maintain the appropriate influenceover the channel of the transistor. A larger actual thickness of ahigh-k material helps reduce or even minimize leakage current in thetransistor.

A floating gate 108 is formed around the gate oxide layer 608. Thefloating gate 108 is conductive, and may be metal, polysilicon, or othermaterials. The coupling film 610, which is also referred to as a caplayer, is then placed on the floating gate 108. The coupling film 610may be a dielectric, or other insulator as specified. The coupling gate102 is then placed on the coupling film 610. A source contact 612, adrain contact 614, and a coupling gate contact 616 are then deposited onthe source 112, the drain 110, and the coupling gate 102, respectively.

The fin structure 606 has a width W and a height H. As the voltages onthe coupling gate contact 616 (which may be coupled to the wordline/control gate 206), drain contact 614 (which is coupled to thesource line 200), source contact 612 (which is coupled to the bit line202) are changed, capacitive coupling occurs between the coupling gate102 and the floating gate 108. The capacitive coupling allows conductionbetween the source contact 612 and the drain contact 614.

FIG. 6B illustrates a birds-eye view of a FinFET floating gatetransistor in accordance with another aspect of the present disclosure.FIG. 6B illustrates that the coupling gate 102 may wrap around thefloating gate 108 in an aspect of the present disclosure. The additionalsurface area between the coupling gate 102 and the floating gate 108increases coupling ratio and decreases the amount of voltage specifiedto induce charge on the floating gate 108.

FIG. 7A illustrates a cutaway of the structure shown in FIG. 6A.Representatively, the gate oxide layer 608 is shown surrounding the finstructure 606, and dielectric layer 700, which may be an inter-layerdielectric (ILD) layer, is shown. Another layer 702, which may be adielectric layer, insulating layer, or interconnection layer is alsoshown on the coupling gate 102.

FIG. 7B illustrates a cutaway view of a FinFET floating gate transistoras shown in FIG. 6B. In this configuration, the offset nature of thecoupling gate 102 with respect to the fin structure 606 illustrates thatthe channel between the source 112 and the drain 110 is controllablewith the coupling gate 102. Control of the channel between the source112 and the drain 110 is possible even when the coupling gate 102 is notin line with the fin structure 606. The coupling gate 102 generatescharge on the floating gate 108 that controls the channel between thesource 112 and the drain 110.

FIG. 8 illustrates a cutaway view of another FinFET floating gatetransistor including an erase capacitor structure in accordance with anaspect of the present disclosure. Representatively, floating gatetransistors 800 and 802 are illustrated. Similar to the structure shownin FIG. 6, the substrate 600 is shown, with a p-well 804 (for NMOSdevices). An n-well 602 similar to that shown in FIG. 6 may be usedwithout departing from the scope of the present disclosure. A finstructure 606 is shown, with the floating gate 108 and the gate oxidelayer 608. The coupling gate 102 and coupling gate contact 616, which ispart of “metal layer 0,” is shown.

An erase capacitor oxide 806 and erase capacitor contact 808 are alsoshown in between the floating gate transistors 800 and 802. In thisconfiguration, the floating gate transistors 800 and 802 are FinFETversions of the program transistor 104, and the erase capacitor oxide806 is an example of the erase gate/capacitor 106. Nevertheless, otherconfigurations of the program transistor 104, which may be a CMOStransistor without a FinFET structure, and other configurations of theerase gate/capacitor 106, are envisioned to be within the scope of thepresent disclosure.

FIG. 9 illustrates a cutaway view of a FinFET structure in an aspect ofthe present disclosure. In particular, as shown in FIG. 9, the couplinggate 102 and the coupling gate contact 616 for the floating gatetransistors 800 and 802 are shown. A spacer layer 900 is shown toprovide an optionally different capacitive coupling between the sides ofthe coupling gate 102 and the sides of the floating gate 108. Toprogram, read, and erase the floating gate transistors 800 and 802,voltages on the coupling gate 102 (which is coupled to the coupling gatecontact 616), the word line/control gate 206, the bit line 202, thesource line 200 (as shown in FIG. 2), and the erase gate/capacitor 106(which is coupled to the erase capacitor contact 808) are selectivelycontrolled to store or remove charge on the floating gate 108.

For example, and not by way of limitation, to program the floating gatetransistor 802, the word line/control gate 206 is brought to a highvoltage, which may be the supply voltage Vcc. This puts charge carriersinto the fin structure 606 from an NMOS access word line (e.g., the wordline/control gate 206). The source line is brought to a programmingvoltage, which may be between 1 and 4 volts. The control gate (CG) 400(or the coupling gate contact 616) coupled to the coupling gate 102 isbrought to a programming voltage, which may be approximately 4-10 volts.The erase capacitor contact 808 is brought to a programming voltage,which may be similar to the voltage on the source line 200. Thesevoltages allow for current to flow through the floating gate transistor802, and hot electron injection allows for charge to inject into thefloating gate 108. The electric charge injection direction 902 betweenthe fin structure 606 and the floating gate 108 is shown. Once thefloating gate 108 is charged, the voltages can be selectively removedand the charge is stored on the floating gate 108.

To erase a floating gate transistor 802 that is programmed, the erasecapacitor contact 808 is brought to an erase voltage, which may beapproximately 6 to 10 volts. The word line/control gate 206, the sourceline 200, the bit line 202, and the control gate/capacitor 400 are allbrought to a low voltage, which may be zero volts. This difference involtage potentials allows for Fowler-Nordheim (FN) tunneling of thecharge carriers stored on the floating gate 108 to migrate across theerase capacitor oxide 806 to the erase capacitor contact 808. The FNpath 906 for erasure of the floating gate transistor 802 is shown.Similar actions occur for writing to and erasing from the floating gatetransistor 800. An additional layer 908 of dielectric or other materialmay be applied to planarize or otherwise seal the structure ifspecified, such that other manufacturing processes may be performed onthe structure shown in FIG. 9. FIG. 10 illustrates that the cap layer904 may reside between the coupling gate 102 and the coupling film 610.The cap layer 904 and the coupling film 610 may be dielectrics or otherinsulators as specified.

FIG. 11 illustrates a cutaway view of an NMOS floating gate and wordline access transistors in accordance with an aspect of the presentdisclosure. When the structure of FIG. 8 is cutaway along the Y-Y′ line,the view of FIG. 11 is seen. The substrate 600 and p-well 804 are shown,and the fin structure 606 shows a fin channel 1100 between the drain 110and the source 112. As voltage is applied to the coupling gate contact616, electric fields are generated in the fin channel 1100. Depending onthe voltages present on the source line 200, the bit line 202, and theword line/control gate 206, current will flow between the source 112 andthe drain 110. The cutaway view of FIG. 11 includes the accesstransistor 402, as the word line/control gate 206 and the coupling gatecontact 616 are separated.

FIGS. 12 through 15 illustrate a process construction flow oftransistors in accordance with an aspect of the present disclosure. FIG.12 illustrates initial steps of depositing layers on the fin structure606. The gate oxide layer 608, which may be a high-k dielectricmaterial, is coupled to the fin structure 606, and the floating gate108. An opening 1200 is made near the floating gate transistor 800, anda layer 1202 of material, which may be a section of the floating gatematerial is deposited. The spacer layer 900 is also deposited and etchedor otherwise manipulated to conform the spacer layer 900 around the finstructure 606.

FIG. 13 illustrates addition of the coupling film 610, and the couplinggate 102, to the floating gate transistor 800. Because the material usedfor the coupling gate 102 is often conductive, a layer 1300 of thismaterial, or other material, is deposited on the layer 1202 and in theopening 1200 for the erase contact.

FIG. 14 shows the erase connection 1400 and the cap layer 904, with thedielectric layer 700 as a planarizing and/or isolation material suchthat the cap layer 904 is substantially planar and electrical contactsare isolated from each other as specified. The planarization allows foradditional processing of the floating gate transistor 800.

FIG. 15 illustrates addition of the coupling gate contact 616 and theerase capacitor contact 808. Additionally the layer 908 may be added,again for planarization and/or isolation of the contacts as specified.Additional layers, such as interconnections, vias, or other electroniccircuitry may be added to the floating gate transistor 800 as specified.

FIG. 16 illustrates an operation control table in accordance with anaspect of the present disclosure. To program a particular transistor,voltages are set for certain operations 1600. The word line/control gate206, the source line 200, the control gate/capacitor 400, erasegate/capacitor 106, and the bit line 202 are controlled based on theselected operation 1600. A read operation 1602, a programming operation1604, and an erase operation 1606 may be performed. Voltages that may beapplied to the lines are shown for when a given transistor is selectedor unselected for the operations used in NVM cells, including MTP memorycells of the present disclosure.

FIG. 17 illustrates a process flow in accordance with an aspect of thepresent disclosure. Representatively, a flow chart 1700 illustrates amethod of fabricating a multiple time programmable (MTP) NVM device. Atblock 1702, fins of a first conducting type are formed on a substrate ofa second conducting type, as shown, for example, in FIG. 6. At block1704, a floating gate dielectric is formed to partially surround thefins.

At block 1706, a floating gate is formed on the floating gatedielectric. At block 1708, a coupling film is formed on the floatinggate. At block 1710, a coupling gate is formed on the coupling film.

Aspects of the present disclosure provides advantages over the relatedart by using a high-k/metal gate process to form an floating gate typeeFlash MTP cell. Further, one aspect of the present disclosure allowsthe use of FinFET structures within an MTP cell. The structures,according to one aspect of the present disclosure, use similarprocessing as related devices. This aspect of present disclosure allowsfor a thickness tunable coupling oxide/high-k film, which may reduce theerase voltage used and improve data retention in the MTP cell. Thecontrol voltage of coupling gate 102 on the floating gate 108 can bepositive or negative, whereas the related art used a positive voltage onthe floating gate 108.

Aspects of the present disclosure also allow for additional coupling ofthe FinFET structure by “wrapping” the floating gate 108 and thecoupling gate 102 around the fin structure 606 as shown in FIG. 15. Thisincreased coupling allows for lower programming (write) voltages in theFinFET structure of this aspect of the present disclosure. Again, thecontrol voltage of coupling gate 102 on the floating gate 108 can bepositive or negative in this aspect of the present disclosure,eliminating the positive-only control of the related art.

In one configuration, a multiple time programmable (MTP) device includesa means for conducting current. In one aspect of the disclosure, thecurrent conducting means may be the fin structure 606, the source 112and the drain 110 and/or other structures configured to perform thetransistor functions recited by the current conducting means. In thisconfiguration, the device also includes means for storing charges. Inone aspect, the storing means may be the floating gate 108 and/or otherstructures configured to perform the transistor functions recited by thecurrent controlling means. The device also includes means forcontrolling logic states. The controlling means can be the coupling gate102 and/or other structures configured to perform the functions recitedby the charge inducing means. In another aspect, the aforementionedmeans may be any module or any apparatus configured to perform thefunctions recited by the aforementioned means.

FIG. 18 is a block diagram showing an exemplary wireless communicationsystem 1800 in which an aspect of the disclosure may be advantageouslyemployed. For purposes of illustration, FIG. 18 shows three remote units1820, 1830, and 1850 and two base stations 1840. It will be recognizedthat wireless communication systems may have many more remote units andbase stations. Remote units 1820, 1830, and 1850 include IC devices1825A, 1825C, and 1825B that include the floating gate transistors 800and 802 or other disclosed structures in the present disclosure. It willbe recognized that other devices may also include the disclosed devices,such as the base stations, switching devices, and network equipment.FIG. 18 shows forward link signals 1880 from the base station 1840 tothe remote units 1820, 1830, and 1850 and reverse link signals 1890 fromthe remote units 1820, 1830, and 1850 to base stations 1840.

In FIG. 18, remote unit 1820 is shown as a mobile telephone, remote unit1830 is shown as a portable computer, and remote unit 1850 is shown as afixed location remote unit in a wireless local loop system. For example,the remote units may be mobile phones, hand-held personal communicationsystems (PCS) units, portable data units such as personal dataassistants, GPS enabled devices, navigation devices, set top boxes,music players, video players, entertainment units, fixed location dataunits such as meter reading equipment, or other devices that store orretrieve data or computer instructions, or combinations thereof.Although FIG. 18 illustrates remote units according to the aspects ofthe disclosure, the disclosure is not limited to these exemplaryillustrated units. Aspects of the disclosure may be suitably employed inmany devices, which include the disclosed transistors, FinFETs, or otherstructures within the scope of the present disclosure.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure may be embodied directly in hardware, in a software moduleexecuted by a processor, or in a combination of the two. A softwaremodule may reside in RAM memory, flash memory, ROM, EPROM, EEPROM,registers, hard disk, a removable disk, a CD-ROM, or any other form ofstorage medium known in the art. An exemplary storage medium is coupledto the processor such that the processor can read information from, andwrite information to, the storage medium. In the alternative, thestorage medium may be integral to the processor. The processor and thestorage medium may reside in an ASIC. The ASIC may reside in a userterminal. In the alternative, the processor and the storage medium mayreside as discrete components in a user terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by ageneral purpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can include RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store specified program code means in the form of instructions ordata structures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method of fabricating a multiple timeprogrammable (MTP) device, comprising: forming a plurality of fins of afirst conducting type on a substrate of a second conducting type;forming a floating gate dielectric to partially surround the pluralityof fins; forming a floating gate on the floating gate dielectric;forming a coupling film on the floating gate; and forming a couplinggate on the coupling film.
 2. The method of claim 1, in which thefloating gate is configured to store logic states of the MTP device. 3.The method of claim 1, in which the coupling film and coupling gatepartially surround the floating gate.
 4. The method of claim 1, in whichthe floating gate comprises an input/output (I/O) device having thefloating gate dielectric with an increased thickness.
 5. The method ofclaim 1, in which the floating gate dielectric has a dielectric constantgreater than a dielectric constant of silicon oxide.
 6. The method ofclaim 1, further comprising forming an erase dielectric coupled to thefloating gate.
 7. The method of claim 1, further comprising integratingthe MTP device into a mobile phone, a set top box, a music player, avideo player, an entertainment unit, a navigation device, a computer, ahand-held personal communication systems (PCS) unit, a portable dataunit, and/or a fixed location data unit.
 8. A method of fabricating amultiple time programmable (MTP) device, comprising: the step of forminga plurality of fins of a first conducting type on a substrate of asecond conducting type; the step of forming a floating gate dielectricto partially surround the plurality of fins; the step of forming afloating gate on the floating gate dielectric; the step of forming acoupling film on the floating gate; and the step of forming a couplinggate on the coupling film.
 9. The method of claim 8, further comprisingintegrating the MTP device into a mobile phone, a set top box, a musicplayer, a video player, an entertainment unit, a navigation device, acomputer, a hand-held personal communication systems (PCS) unit, aportable data unit, and/or a fixed location data unit.
 10. A multipletime programming (MTP) device, comprising: means for conducting current;means for storing logic states which control the current in the currentconducting means; and means for controlling the logic states stored onthe logic storing means.
 11. The MTP device of claim 10, furthercomprising erase means for removing the logic states stored on the logicstoring means.
 12. The MTP device of claim 11, in which the logicstoring means partially surrounds the current conducting means.
 13. TheMTP device of claim 11, integrated into a mobile phone, a set top box, amusic player, a video player, an entertainment unit, a navigationdevice, a computer, a hand-held personal communication systems (PCS)unit, a portable data unit, and/or a fixed location data unit.